STX-R charging voltage - battery light flashing

My battery charging light is on...battery has 12.3 volts when running vs 11.9 volt off. Battery light is on. I just bought the ski (65hours use) and the light went off during my test ride but is now on. I just removed the battery and resurfaced the battery and connections...nothing wrong here or at ground to motor.

What should I check next? Don't have a shop manual yet (where should I pick one up?).
Thanks....

The service manual states the voltage has to rise above 12.5 before the light will turn off?

Is this the original Yulsa battery? Mine is like Jordon's. My light will come on during starting and then stay on for 1-2 minutes afterwards. Honestly I'd just watch it and see what happens. Could be a bad rectifier, or an older battery. 12.3 is alittle low for charging voltage.

Now it is behaving better....goes off within a five minutes or so. During my first couple of rides, the light did not go out but seem to be fine. Since this is new to me, I thought I had a problem. The person who sold it to me also gave me a new battery in a box to solve the problem.
Thanks for the manual....